From Greg Laden's blog:
The amount of ice lost to the sea from Antarctica has increased by 75 percent in the last 10 years. This is the result of an increase in glacial flow. It had previously been thought, and perhas was the case, that Greenland ice loss outpaced the Antarctica. This is no longer the case.
An article coming out in the next issue of Nature Geoscience, by Rignot et al ("Recent Antarctic ice mass loss from radar interferometry and regional climate modelling") is the most detailed study of this phenomenon to date.
There are two factors that affect the flow of ice into the sea at the edge of the southern continent. One is the amount of snow that falls across the continent, which might increase the total amount of water trapped in glacial ice, or might increase the speed of glacial movement towards the sea. The other is how rapidly the glaciers slide into the sea at the glaciers' "grounding sites,"
Global warming may have increased the amount of precipitation in Antarctica, which could increase the total volume of water trapped in this mass of ice. This would partially offset sea level rise caused by glacial melting in the Arctic and in mountain glaciers. However, warmer seas surrounding Antarctica and warmer air temperatures can cause the melting edge of the glaciers to mlt faster. When the grounding edge of the glaciers falls apart due to warm air or water, the mass of the glacier behind this leading edge moves more quickly to the sea.
http://scienceblogs.com/gregladen/2008/01/new_study_of_antarctic_ice_los.php